Add BUILD.gn, OWNERS and README.webrtc

Add BUILD.gn, OWNERS and README.webrtc

This is needed to be able to DEPS in the entirety of
winsdk_samples into WebRTC when we move away from
symlinks.

BUG=webrtc:5006
R=charujain@webrtc.org

Committed: 6e4f93cc0c2f597547449cbaa80a6af629215a63

[kjellander_webrtc, 2016-12-14 12:17:58]

kjellander@webrtc.org changed reviewers:
+ charujain@webrtc.org

[kjellander_webrtc, 2016-12-14 12:17:58]

With this, I'm moving the files currently located in third_party/winsdk_samples
of a WebRTC checkout into the separate repo at
https://chromium.googlesource.com/external/webrtc/deps/third_party/winsdk_sam...
which contains the source code. Since this repo is not auto-mirrored in any way,
it might as well contain these files as well.

That will unblock me from one of three dependencies that sits in
https://chromium.googlesource.com/external/webrtc/+/master/third_party/ which
conflicts with the work I'm currently doing in
https://bugs.chromium.org/p/webrtc/issues/detail?id=5006 (where all of
third_party will need to be replaced with a Git subtree mirror).

[charujain, 2016-12-14 13:35:35]

lgtm

[kjellander_webrtc, 2016-12-15 12:53:59]

Description was changed from

==========
Add BUILD.gn, OWNERS and README.webrtc

This is needed to be able to DEPS in the entirety of
winsdk_samples into WebRTC when we move away from
symlinks.

BUG=webrtc:5006
==========

to

==========
Add BUILD.gn, OWNERS and README.webrtc

This is needed to be able to DEPS in the entirety of
winsdk_samples into WebRTC when we move away from
symlinks.

BUG=webrtc:5006
R=charujain@webrtc.org

Committed: 6e4f93cc0c2f597547449cbaa80a6af629215a63
==========

[kjellander_webrtc, 2016-12-15 12:54:01]

Committed patchset #1 (id:1) manually as
6e4f93cc0c2f597547449cbaa80a6af629215a63 (presubmit successful).